In the longitudinal study of children of affectively ill and well parents, we have utilized a multi-source and multi-method approach in assessing the children. Of particular interest are comparisons of (1) mothers' and fathers' reports, (2) parents' and children's interviews at different developmental stages, and (3) psychiatric interview data and direct observations of behavior. Also of interest is what constitutes the best combinations of data sources for evaluating the psychosocial functioning of young children. Interviews with the children (CAS, DICA, family relationships) , reports from parents (DICA-P, CBCL), teacher reports (CBCL) , and extensive observations inform us about the children's Psychiatric and psychological status. These analyses are in progress.